Openthread with FreeRTOS

[Asgeir]

Hi!
I've successfully set op an OpenThread MQTT broker using a Rasperry Pi and nrf52 dongle and I am able to publish and subscribe to and from my computer by flashing the mqttsn_client_subscriber and mqttsn_client_publisher examples to my nrf52840 DK.

I want to incorporate thread communication into a larger project on the nrf52840 DK using FreeRTOS. My first step has been trying to modify the mqttsn_client_subscriber example to incorporate FreeRTOS. However I have not had much success.

Does the SDK provide examples of OpenThread with FreeRTOS or are there other sources I can consult?

[Edvin]

Hello,

There is one example that uses the openthread stack and FreeRTOS:

SDK_for_Thread_and_Zigbee_4.1.0\examples\thread\freertos_coap_server

Perhaps you can use this example for reference.

Best regards,

Edvin

[Asgeir]

Hi!
I've tried this unsuccessfully.

I modified the mqttsn_client_subscriber example some, making it connect to the broker and subscribe to topic automatically, not using the buttons.
This solution works well. 



However when i try to implement the same solution in FreeRTOS, using the freertos_coap_server as a reference, it doesn't work. The program does not connect to the gateway etc. 


There seems to be an issue with running the mqttsn_evt_handler, perhaps this is related to using the app_scheduler in the program? I am not sure, but the events are not triggered. 

Here is my code: https://github.com/hunshamar/freertos_openthread

Do you have any suggestions for making this work? I am not too experienced with FreeRTOS or the nordic SDK, so any help would be appreciated. 

-Asgeir

[Asgeir]

This did not make any difference, unfortunately. 

[Edvin]

How did you erase the dongle's flash? 

If you haven't tested it, can you please try the hex file found in Jørgen's answer from this post?

The hex file found in flasherase_nrf52840_dongle_sdk16\flasherase\hex\flasherase_pca10059.hex will erase the flash for you if you flash it from nRF Connect for Desktop.

Then you can program it with the correct FW again after that.

BR,

Edvin

[Asgeir]

I'm using the nrf52840 DK for developing, not the dongle. 

For erasing the flash i ran the "make erase" command from the makefile.  

I tried flashing the hex file using nrf connect, but it made no difference either. 

[Edvin]

using a Rasperry Pi and nrf52 dongle

 But you have an nRF52 dongle connected to your RPi? Can you try to erase this one?

[Asgeir]

The dongle is connected to the MQTT broker, yes. But this works without any problem, the problem is not in the RPi broker. When running the openthread project on nrf52840 DK without freertos everything works. 

The problem is when i try to implement FreeRTOS in the thread project on the development kit that I'm trying to connect to the thread network running on the RPi. 

The code i attached to a previous comment explaining the problem, https://github.com/hunshamar/freertos_openthread,  I have two openthread programs that I can flash to the development kit, one using FreeRTOS which is not working, and one not using FreeRTOS that is working with openthread. 

[Edvin]

Then what will happen if the RPi broker already have network data on the DK, that it assumes that the DK also has? Then the DK starts up without any stored network data. 

Please give it a go. It is a matter of uploading the hex file from my earlier reply, and re-flashing it. Then let me know if it still behaves the same.

[Asgeir]

I gave this a try, but unfortunately it did not work. I even tried a brand new nrf52 dongle.
The problem seems to be with the FreeRTOS program. I tried adding another task that only toggles an LED on the board, and this one freezes as well. The problem seems to be with the mqqtsn_client_search_gateway() function that is run at the start of the program.

When i exclude this piece of code at least the led blinking tasks runs normally. But if I run this function the program seems to halt. 

Also if I just comment out all the FreeRTOS -stuff and run the openthread-task as a while-loop it works. So there seems to be some conflict with FreeRTOS and the mqtt event handler or something similar.  

[Edvin]

Ok. Thank you for checking. Can you please zip your project (preferably the one that also toggles the led, which also freezes) here, so that I can try to recreate it on my DK.

Best regards,

Edvin

[Asgeir]

I uploaded it to github,  https://github.com/hunshamar/freertos_openthread, which can also be downloaded as a zip. But do you want the full SDK folder with the project zipped? 

-Asgeir

[Edvin]

I saw that repo, but which of the projects is it? And what IDE did you use to set up the project? I tried the freertos_coap_server\pca10056\blank\ses and armgcc, but none of them compiled in an unmodified SDK2.0.0. Where should I place the project file, and what IDE do you use? Please make sure that it compiles in an unmodified SDK.

SDK2.0.0 is a bit old, so you can consider to move to SDK4.1.0, but we can look into it in the SDK2.0.0 first.

BR,

Edvin